The behavior of acquire+release annotation handling has changed in
https://reviews.llvm.org/D49355 which breaks the build with the new
Clang. However, as has been pointed out, the acquire+release isn't
the right way to prevent double locking as the annotations negate
each other; the correct way is to use excludes or negative requires.
Using excludes annotations also requires using std::lock_guard instead
of std::unique_lock because the latter doesn't have the thread
annotations due to deferred locking which is not needed in Flutter and
so std::lock_guard is a sufficient alternative.
* Reland "Added IsolateNameServer functionality (#5410)"
This reverts commit c3976b3c7183f479717bffed3f640fb92afbd3dc.
* Fixed issue with isolate_name_server_test which caused test to timeout
* Disabled thread_annotations on Android as they aren't supported in the
NDK headers for std::mutex. Readded thread annotations to
IsolateNameServer.
* Added IsolateNameServer functionality, which allows for the association
of string names with isolate SendPort ids that can be used to establish
inter-isolate communications.
